A preliminary analysis of the morphological adjustment within and downstream of a lowland river subject to river restoration

✍ Scribed by D.A. Sear; A. Briggs; A. Brookes

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 320 KB
• Volume: 8
• Category: Article
• ISSN: 1052-7613
• DOI: 10.1002/(sici)1099-0755(199801/02)8:1<167::aid-aqc264>3.0.co;2-7

✦ Synopsis

1. Geomorphological models developed from studies of alluvial river channel processes can be used to predict river channel response to restoration. These models suggest that restoration can significantly affect modified and unmodified reaches downstream, and that sediment yields from these reaches may remain enhanced for some time as the river system adjusts to restoration. A preliminary test of this model has been undertaken on a recently restored lowland river in the UK.

2. Adjustment is characterized by initially high rates of morphological change controlled by sediment type and stability. Specific adjustments include the growth of in-channel sediment stores and banks exposed by erosion that modify the geometry of the restored river. Downstream impacts show aggradation of the river bed and enhanced morphological diversity.

3. The results of the study indicate that whilst general geomorphological models are applicable to predicting impacts of lowland river restoration, the specific adjustments are controlled by the availability and type of substrate, the power available to transport the substrate, and the nature of the restored channel morphology. The study also shows the need for objective methods of assessing morphological diversity before and after restoration in order to assess the success of the morphological goals of river restoration projects.